The No.1-seeded Williams lost just 14 points in her eight service games and broke the No.3-seeded Radwanska's serve four times - twice in each set - to win the one-hour, 12-minute contest. Williams' numbers were phenomenal - 31 winners, 21 unforced - Radwanska was a more modest 5 and 7.
"Playing against Agnieszka, she plays like magic, she can move the ball left and right - she can do anything with her shots," Williams said. "So for me today it was just important to try to stay ahead of her, or one step ahead of her. I just tried to do that today and I'm happy with how things went."
"She's a player who doesn't really let you play," Radwanska said. "She's really pretty much attacking everything, all the serves, all the returns, and when she's really having her day, it's really tough.
"I think she played very well today from the beginning until the end. She was just playing too well."
Radwanska is now 0-7 lifetime against Williams - what makes the World No.1 so difficult to beat?
"I think her ranking and how many points she has right now are proof that she's having a really good year and playing on a very high level the whole year," Radwanska said. "And on the court she's very consistent, always playing very aggressive, deep balls, and pretty much attacking from every point.
"It's really hard to find your rhythm and stay in the game. She dictates pretty much everything."
What will Radwanska do if they play at the TEB BNP Paribas WTA Championships - Istanbul?
"Maybe I will just play with my left hand - maybe that will work!" she joked.
Williams' win over Radwanska was her 72nd match win of the year, by far the most match wins she has ever had in a year - previously the most she had was 58 in 2012. She will also be going for her 10th WTA title of the year, which would be the most since Justine Henin won 10 WTA titles in 2007.
Awaiting Williams in the final will be No.8 seed Jelena Jankovic, who won her semifinal earlier on.
Williams leads Jankovic in their head-to-head series, 6-4. Jankovic is one of only two active players who has recorded four or more career wins over her - Venus Williams has 10 career wins over her.